Patients who have taken popular GLP-1 medications for weight loss aren't saving themselves or their health plans any money, at least not right away.

Eagan-based pharmacy benefits manager Prime Therapeutics issued that disappointing finding this week after analyzing the health care spending of thousands of patients who started taking GLP-1 medications in 2021, comparing them with similar patients who didn't take the drugs.

Spending was $4,206 higher per patient in the second year after they started taking the GLP-1 medications compared to the group of patients who didn't take it, primarily because of the costly medications themselves.

"It's too soon to conclude whether these drugs will have a return on investment from a total cost of care perspective," said David Lassen, Prime's vice president of primary clinical services. "We didn't expect to see that in two years, but we were hopeful that we would start to see something!"

GLP-1 is the name for the blockbuster class of drugs such as Wegovy, Mounjaro and Zepbound that mimic a hormone called glucagon-like peptide 1, which indicates fullness and reduces appetite. Patients have reported dramatic weight loss on the medications, which researchers hoped would result in a reduction in obesity-related health complications and spending to treat those complications.

The Prime research confounded those hopes, at least in the short term. Only one in seven patients in the study group were still taking brand-name GLP-1 medications after two years, despite having continuous insurance coverage.

The study is the third in a series released by Prime as it tracks this study group, which started with 3,000 patients but has less than 500 left because of the number who discontinued their medication. Some GLP-1 medications such as Ozempic have been approved to manage diabetes, but the study focused on patients who didn't have this chronic disease and started taking them for weight loss.

"People don't seem to be staying on the drug as much as we had hoped," said Pat Gleason, Prime's assistant vice president for health outcomes.

Even those who stuck with the medications showed no reduction in medical spending or in new diagnoses of diabetes, heart attacks or joint replacement surgeries. Gleason said the study didn't cover all potential impacts of the drugs. It's possible, for example, that GLP-1 usage reduced sleep apnea, a known consequence of obesity.

Prime's conclusions from this ongoing study have drawn skeptics, given its role as a pharmacy benefits manager that approves or denies drug coverage for patients covered by Blue Cross and Blue Shield of Minnesota and other health plans around the country.

A 38-year-old Columbia Heights man named Caleb said his cholesterol, blood pressure and insulin levels returned to normal ranges after he started taking GLP-1 medications in March 2022 and lost more than 100 pounds. He said he had unrestricted access before Prime imposed a prior authorization requirement and then changed policies in a way that caused him to lose coverage. He is now using a savings card from Eli Lilly to cut his out-of-pocket costs, but is still paying $550 for a one-month supply. The cost will increase to $650 next year.

"The study conducted by Prime Therapeutics is inherently flawed, considering their role in controlling access to medications," said Caleb, who spoke on the condition that his surname not be used because of the public backlash over obesity and the medications.

Prime is releasing its newest results on its own, but published its first study in a peer-reviewed scientific journal and is planning to present the latest results at a medical conference next spring.

The new study also found in the GLP-1 group an elevated rate of pancreatitis, a known potential complication of the medication. The complication rate was only 0.4%, but that still was a notable increase in the condition, which is marked by swelling and pain in the pancreas, Gleason said.

Dr. Jeremiah Eisenschenk said the findings match his experiences at Essentia Health Brainerd Medical Weight Management, where some patients have seen "profound" benefits from the medications.

"I can think of a few patients who have probably avoided hospitalizations and are off some other meds and are delaying knee replacements because of the weight they've lost," he said, but he could recall an equal number of patients struggling with side effects or losing too much muscle mass along with fat.

"For others who cannot tolerate, afford, or safely acquire these agents, we are de-escalating doses and discontinuing them," he said, adding that patients regardless of medications should be adhering to high-protein, low-sugar diets, and taking part in resistance training to maintain muscle mass.

Prime similarly is using the results to promote its KeepWell program, which can pair members' medication usage with personalized lifestyle strategies to maximize the changes of weight loss and health benefits.

While insurance coverage wasn't a barrier in the Prime study group, it has been for others as employers and health plans offset the high costs by limiting who qualifies for the medications. Even health care providers have been forced into cuts. Hennepin Healthcare eliminated coverage of GLP-1s for its workers seeking them for weight loss alone, while Mayo Clinic imposed a $20,000 lifetime cap on usage.

Out of pocket costs for GLP-1 medications have ranged around $900 to $1,400 per month for patients without insurance coverage, though some have been able to obtain discount cards and coupons from manufacturers.

Dr. Carolyn Bramante at the University of Minnesota Medical Center said she is constantly advocating for insurance coverage for her patient's medications. The weight management specialist believes private insurers should cover the drugs because they will prevent disease, just over a much longer timeframe.

"The cardiovascular disease and kidney disease and cancer outcomes that we can prevent with these medications are most likely going to happen when individuals are over age 65," she said, even if people take them to lose weight at much younger ages.

Prime's study had limitations. Its results were based on insurance claims, so it couldn't track patients who pay for GLP-1 medications on their own or switch to alternatives. Compounding pharmacies were allowed to make similar versions of GLP-1 medications while the brand name supplies were in short supply. The Food and Drug Administration recently removed the drugs from its drug-shortage list, but is still evaluating whether compounded alternatives can be offered in certain circumstances.

The study also focused on people who started on GLP-1s when only certain brand-name versions were available. Prime is planning a new study looking at patients who started on GLP-1 drugs in 2022, when Lilly's Zepbound version reached the marketplace.